1. Field of the Invention
The present invention concerns the general technical field of non-invasive treatment of an ocular pathology.
It more specifically concerns a device and method for generating focused, planar or unfocused ultrasound of high or low intensity for the treatment of an ocular pathology such as glaucoma.
2. Description of Related Art
Glaucoma is an optical neuropathy i.e. a disorder of the optical nerve due to high intraocular pressure (IOP).
The eye is a hollow structure composed of two segments: the anterior segment between the cornea and crystalline lens, and the posterior segment between the crystalline lens and the retina. The anterior segment contains a transparent liquid called “aqueous humour”.
The aqueous humour is formed in the posterior chamber of the eye's anterior segment by the ciliary body. The liquid which is generated at a relatively constant rate then passes around the crystalline lens through the pupil opening in the iris and into the anterior chamber of the eye. The aqueous humour is then evacuated through the trabeculum and Schlemm's canal.
When the aqueous humour is no longer evacuated sufficiently rapidly it builds up leading to a rise in IOP. An increase in IOP compresses the axons in the optic nerve and may also compromise the vascularisation of the optic nerve. High IOP over a long period may cause total loss of vision.
The sole therapeutic approach currently available to treat glaucoma consists of reducing intraocular pressure:                either by improving drainage of aqueous humour;        or by reducing the production of aqueous humour.        
Different devices are known for reducing the production of aqueous humour based on the principle of cyclophotocoagulation. Documents DE 44 30 720 and WO 02/38078 describe devices each comprising an applicator generating energy for burning a spot region of the ciliary body so that the ciliary body produces less aqueous humour. The user positions the applicator on the white part of the eye in contact with the sclera at an angle of incidence perpendicular to the surface of the eye. The user then generates a laser burst in order to burn the spot region of the ciliary body. The applicator is then moved by the user in order to burn a following spot of the ciliary body.
One disadvantage with these devices is that they only allow one spot region of the ciliary body to be treated at one time, which means that it is necessary to repeat the applicator positioning operations and to apply the laser a plurality of times to treat the entire circumference of the eye. This repeating of positioning and laser application operations increases surgery time and the risk of error.
To overcome these disadvantages document WO 2009/103721 particularly proposes a device for treating an ocular pathology comprising a ring having a proximal portion suitable to be in contact with the eye and a distal portion suitable to receive means for generating high intensity focused ultrasound beam. The means for generating ultrasound comprise six transducers having a concave profile in the form of cylinder segments positioned on a cylindrical supporting ring.
With this device it is possible to treat glaucoma in a single step. However the manufacturing of means to generate high intensity focused ultrasound beam of and in particular the positioning of the transducers on the cylindrical support may be difficult to implement.
An aim of the present invention is to propose an easier device to manufacture than the device described in WO 2009/103721.